U.S. Pat. No. 5,234,485 to Bolsing discloses a method of immobilizing a contaminant comprising mixing the contaminant with a reaction partner which is capable of chemically interacting with the contaminant to form a water-insoluble reaction product. The reaction partner is mixed in the form of a hydrophobic solid preparation, which is either obtained by grinding the reaction partner with an inert material and treating it with a hydrophobic agent or a material which contains the educt or reaction product of a dispersion by chemical reaction preliminary treated with a hydrophobic agent, the mixture being conducted to form a soil or soil-like material with cohesive constituents of a clay-like structure. The Bolsing compositions may comprise stearic acid, alcohol, quicklime and water. These compositions specifically call for mixing the quicklime and water before contacting the quicklime with the waste or hazardous material. Thus, Bolsing teaches away from the present invention.
U.S. Pat. No. 4,018,679 to Bolsing (Bolsing '679) discloses a method of rendering harmless an oily waste material comprising mixing an alkaline earth metal oxide with a surface active agent which delays reaction between the alkaline earth metal oxide and water, combining the mixture with the oily material, and reacting the alkaline earth metal oxide charged with the waste material with approximately the stoichiometric amount of water to convert the alkaline earth metal oxide to the hydroxide. The alkaline earth metal oxide is preferably calcium oxide and advantageously it is also mixed with a hydrophobizing agent prior to mixture with the oily waste material. Proportions are desirably such that the end product is a solid which can be used as a lining in road construction and at dump sites. The Bolsing '679 compositions may comprise quicklime, water, a stearic acid and alcohols. Bolsing '679 does not teach or suggest using its process for breaking down PCB containing waste or hazardous material. Bolsing '679 also teaches to reduce the exothermic heat generated by including magnesium oxide with calcium oxide. On the other hand, the present invention recognizes that higher temperatures (400.degree. to 600.degree. F.) are optimally suited for breaking down PCB containing waste and hazardous material. Additionally, Bolsing '679 teaches that calcium hydroxide absorbs the oily waste. Conversely, in the present invention, absorption of the waste/hazardous material occurs before reaction between water and quicklime. Thus, Bolsing '679 teaches away from the present invention.
U.S. Pat. No. 5,108,647 to Bolsing ("Bolsing '647") discloses a method of dehalogenating a halogenated hydrocarbon in the presence of a nucleophilic reaction partner, comprising dispersing the halogenated hydrocarbon by chemical reaction (DCR), and dehalogenating the resulting finely dispersed reaction product by means of a strictly chemical conversion with the nucleophilic reaction partner at a temperature between ambient temperature and approximately 950.degree. F. Bolsing '647 does not teach or suggest the coating of the quicklime with an aliphatic salt of sodium or the like for the purpose of rendering the quicklime organophilic, prior to contacting the quicklime with the halogenated hydrocarbon (waste). In fact by teaching that the halogenated hydrocarbon (waste) is contacted with untreated quicklime, Bolsing '647 teaches away from the present invention. Additionally, by teaching the use of external heating in most if not all of the disclosed examples, Bolsing '647 again teaches away from the present invention.
U.S. Pat. No. 5,186,742 to Hoffman et al., discloses a process wherein arc dust waste produced by electric arc furnaces are conducted to silos and converted to a reusable co-product by means of an addition of a special blend of high calcium and dolomitic quicklime, calcium stearate and pulverized waste paper. The mixture is pressed into compact pellets which, due to their impact integrate and improved shelf life can be pneumatically conveyed intact into storage silos for recycling of the waste electric arc flue dust into the furnace melt. Compliments of the arc-dust deemed leachable and hazardous in landfills such as zinc, lead and chromium are increased in concentration to a point where it is economical to extract them for resale. Hoffman's compositions for converting arc-dust waste to a useful product may comprise quicklime, calcium stearate and pulverized waste paper.
Japanese abstract number 58-79509 to Tashiro discloses another use of quicklime and slaked lime (an OH containing compound), in connection with a waste treatment process.
U.S. Pat. No. 4,329,090 to Teague et al. discloses a method for treating surface earth layers to achieve stabilization, strength and permeability, by slaking quicklime in a mixing tank so as to cause elevated temperatures and so as to form a hydrated lime slurry and working said slurry into the soil to be stabilized. There is no suggestion or motivation in Teague to use quicklime for the breakdown of waste or hazardous materials.
In September 1991, the United States Environmental Protection Agency published an investigative report entitled "Fate of Polychlorinated Biphenyls (PCBs) in Soil Following Stabilization with Quicklime." This report dealt with the reports of researchers on destruction of PCBs in contaminated soil by the application of quicklime. EPA observed that these research reports were based on retrospective data from site remediation programs, anecdotal information and results of one bench-scale project. EPA investigation was conducted to verify claims that use of quicklime alone can promote decomposition of PCBs. Based on this investigation, EPA concluded that the use of quicklime (as suggested by researchers), as an in-situ treatment for removal of PCBs was not supported by their findings. The following excerpts from the EPA report are telling:
Minimal evidence of PCB dechlorination was observed . . . The destruction of PCBs by application of quicklime to contaminated soil, sediment or sludge has thus not been demonstrated, either by controlled benchtop experiments or by retrospective analysis of a sample from a remediation site where the process was applied. Evidence of PCB volatilization suggests that use of reactive quicklime as an in-situ treatment may even be contraindicated due to the potential for migration of PCBs as vapor or airborne particulates . . . (emphasis supplied)
This report clearly teaches away from utilizing quicklime to break down waste or hazardous materials containing PCBs.